For many, Cartesian dualism has lost the battle owing to the blows struck by the neurosciences and, in particular, functional cerebral imaging. In an article (Dualism Persists in the Science of the Mind)co-authored by Steven Laureys from the Coma Science Group at ULg, he reports on the conclusions of a vast survey he initiated: despite all, dualist conceptions still remain popular. Journey to the land of the “soul” and consciousness.

Already in 1983, Jean-Pierre Changeux wrote in L'homme neuronal: “L'identité entre états mentaux et états physiologiques ou physicochimiques du cerveau s'impose en toute légitimité” (The identity between mental states and physiological or physicochemical states of the brain is definitely legitimate). Since then, studies based on functional cerebral imaging have increased and each one has added to the corroboration of this theory. In principle, Cartesian dualism is dead since everything indicates that the mind does not emanate from an immaterial substance outside the body. Modern science therefore joins forces with the materialist conceptions of the Enlightenment Philosophers. For Diderot and Baron d’Holbach, for instance, the mind is a property of the brain. And since, according to them, the latter obeys the laws of natural determinism, it cannot exist of its own free will. Hence, the belief in a free will must be slipped into the same coffin as spiritualism. In his Système de la nature, Baron d'Holbach writes: “Our life is a line that nature orders us to follow on the surface of the Earth without ever being able to stray from it for one moment.”

Today, there are many supporters of determinism among neuroscientists. Concerning those who are endeavouring to save the idea of free will, such as the Nobel Prize winner Gerald Edelman, the philosopher Jean-Noël Missa, from the Free University of Brussels, states that they are hiding behind inconsistent materialism. Edelman, for instance, speaks of a primary consciousness and a superior consciousness, which man can reach thanks to language. This creates a phenomenon of distance that shows a glimpse of a way out from genetic and epigenetic double determinism – the impregnation of our cerebral tissue even by our individual “history” – that would allow us to imagine a real process of self-determination. However, for many, it is an ad hoc solution grafted by Edelman onto his general model of the selection of neuronal groups (“neuronal Darwinism”, according to his own terminology). “On the issue of language and superior consciousness, Edelman evokes the idea of a magician making a rabbit appear out of his hat”, says Jean-Noël Missa.